Factorio Forums

Hi guys,

Some friends and I were playing in an MP session when we all suddenly experienced a desync. After further troubleshooting, we've narrowed it down to when any of us place a smart inserter pulling from a belt into a chest. When in the smart inserter logistic network condition signal-selection screen, once an item is chosen that causes the inserter to begin moving items, the game desyncs (usually when the second item stack is picked up) for all players and does not recover properly.

I've attached a desync report below, and here are the system specs:

Server:
VirtualBox VM with 4 vCPUs and 4GB RAM running on 2x Xeon 5620s, running headless 0.12.5 x64 (updated 8/28 from 0.12.4) on Ubuntu 14.04

Client 1:
Win8.1 desktop with Core i5-2600K and 16GB RAM, nVidia GTS250

Not sure if anyone else has seen anything like this with 0.12.5 yet or not. Haven't ruled out the possibility of a partially corrupt save or something odd like that.

-Axemann
<edit> Fixed topic

I have also experienced this bug.

Narrowing this bug down, the desync seems to originate from changing a circuit condition.

We've been playing a multiplayer map since 0.12.2, and in the update to 0.12.5, smart inserters do seem to work fine.

Until we try to change the smart inserter's condition. This reliably desyncs the game, but it's all good after re-syncing.

Same here. OP forgot to post version in topic. Someone should fix this.

I am having the same issue, though for me it is actually with changing ANY of the devices with circuit conditions. In my case, it was both a Smart Inserter a Small Pump, and a Lamp. Doesnt matter if I change to a static value or a different signal. The moment I hit "Set" it will cause a desync. And sometimes, the Desync will also corrupt the world.

It only happens when connected to my linux headless multiplayer server. Replicating the same actions in Single-Player or by hosting a Multi-player server locally functions fine. I believe it involves changes to the circuit system not being sent upstream correctly, which causes a desync when the server tries to evaluate a different figure to the client.

Headless server is running RHEL Server 7.1 and Factorio 0.12.5 linux x64
Local machine is running Windows 7 and Factorio 0.12.5 windows x64

I have tried this in multiple worlds, with and without mods, and even in a world that I hadnt touched since 0.11 (updated old install folder, migrated world, built a test setup, tested it, stripped the server back to unmodded, uploaded the world and restarted it. server behaved the same way.)

EDIT: In case you wanted to test it, here is the world that I built the test setup in.
Its pretty basic. will move excess of 40 wood into middle chest, will move wood into right chest until it has 70. changing any of those values while in headless multiplayer causes the desync. I did try adding a lamp on the server, and it was all fine until the second I added wood to the chest that the lamp was connected to.

Sugguest topic be changed to "0.12.5 Reproducible crash on interacting with Circuit Conditions"

Thanks for the report. This has now been fixed for 0.12.6.

Thanks for the quick fix!